I've limited it to US buyers just because I want to send it by a traceable method (UPS, FedEx, DHL) and haven't had the time to figure out what overseas shipping on the transformer (heavy!) would be, plus that is a US transformer. Wouldn't work on 50 Hz (would overheat) and likely wouldn't fit the wall plug in another country. If you have an international DHL account that would bill to a recipient account number (you pay shipping), and can get a transformer that works in your country (cheaper to ship without including that transformer!), I may consider it - just PM me.

This is a 100% true-to-the-BOM unmodified build with all parts straight from Mouser (except the Tenergy batteries), as required by RocketScientist's license terms for commercial sales. As noted in the eBay writeup this one even has one of the original pots before they went out of stock at Mouser.

No box or front panel included, but I am in for a few panels on the group buy when they start shipping in a few weeks. If interested that would be an additional $15 plus whatever shipping is. But no money accepted for that now - I want to wait to have the panels in hand first.

And the best part.... I'm donating $5 of the sale proceeds to DIY Audio!

For DIY Audio folks I would be willing to include a black B2-080 box for the listed price ($149) - that isn't in the eBay listing. Just message me about it on eBay with your DIYA forum name. I haven't included it in the listing since you have to connect a ground wire from the board to a hole you would have to drill in the box and sand away some anodization, as NwAvGuy describes in his blog. I think that would be beyond some of the general public. The boxes are around $11 at Allied Electronics plus around $6 in shipping and another $5 handling if the order is under $25, so the box is up to a $22 value. Also no front panel as noted in the listing.

$5 donation goes to DIY Audio again, regardless of who buys it. I've ready donated for the last one.

I will have a few (3-4) that I can sell in Eu. I will wait until I have tested the low battery fix and maybe another issue I'm tracking down. Aerohoff will probably run another batch as will Jokener so supply will be good. Now, we have an excellent headphone amplifier - what about a whole set? I have been annoying the DIY audio reference speaker wannabees but I believe it is best to leave the speakers to everyone to sort out by themselves.

From Santa I would like:

1: A good media reader that reads different media
2: A good DAC, bit perfect 32/384
3: A good preamp
4: A good poweramp
5: Murdoff silver/gold wire so that I can complete my IC project
6: Of course, piles of good music I haven't heard before.

Turbon - yep, the world should be well supplied with assembled O2 boards going forward!

I bought 4 PCBs in the group buy and bought parts for all 4 at the same time from Mouser. I had originally intended to notch out the battery area on one board and insert 4 of the 9v NiMH batteries, using a B3-080 case (they would fit), for a higher-voltage +/-18V rail O2. Then use a second board as a "front end" for the Wire amplifier board (voltage gain stage, volume control, and DC blocking). But I've since abandoned both ideas. So I'm selling off the 3 unmodified boards and keeping the one I've applied all my modifications to. One down and two to go!

Relisted with a price drop to $99. Sorry but no included case at this price. This one has the Bourns pot option on the BOM and the 16VAC 400mA transformer. As per the eBay listing though I can add a B2-080 case for $17 additional.

Also a final third one for sale. $109 for this one, which has the Alps 15mm pot option from the BOM (those are now out of stock at Mouser!), the 1000mA 16VAC transformer and gain resistors in sockets. Same deal on the case, none included but I can add a B2-080 case for $17 more.

So the Bourns pot version is now re-listed as an auction started at $0.99. I have to sell it for whatever the auction goes for by the eBay rules - no reserve - so here is a chance to get an O2 for cheap.

Yes it did! Someone got an unexpectedly good deal on that one - $48 including the adapter and free shipping. I won't be trying an auction again. Last I heard JDS labs is selling assembled O2s for $95 without adapter, case or shipping. That's OK - someone got an O2 to enjoy out of the deal.

I've have one more up for sale as a fixed price with the B2-080 case, then I'm out of the sales business. Whenever the front panels from the FP group buy arrive I'll be bumping the price up again and adding a front panel as a completely assembled unit. If this one doesn't sell I'm just keeping it!